濒危植物——长喙毛茛泽泻的雌雄配子体发育

长喙毛茛泽泻 Ranalisma rostratum stapf 小孢子母细胞的减数分裂过程为连续型,四分体为左右对称型。成熟花粉为三胞花粉。花药绒毡层为变形绒毡层。雌蕊由多数单室子房构成,每子房中含一具双珠被、薄珠心的倒生胚珠。胚囊发育为葱型。成熟胚囊中三个反足细胞退化;二个极核分别位于中央细胞的两端,其体积相差明显。这种极核分布可能与反足细胞过早退化有关。     

不同生境内濒危植物长喙毛茛泽泻种群数量动态比较

湖南茶陵自然种群动态在一年内表现为春季数量下降，以后振荡变化。在以莼菜为主的样方中，种群在夏季以后一直呈增加趋势，至冬季末数量下降；在杂草拥挤的样方内，种群基本呈下降趋势。湖北武汉，网室中迁地保护的种群生长在理想条件下，单一种群呈逻辑斯缔（Ｌｏｇｉｓｔｉｃ）增长，方程为Ｎ（株／ｍ２）＝８４０１＋ｅ４．４７７－０．２６４ｔ。江西东乡回归原产地的种群在回归当年经过精心照顾，种群呈增加趋势，次年随着杂草茂盛生长，种群数量迅速下降，种群具消失的危险。长喙毛茛泽泻种群数量的变动很大程度上受水位变化和杂草干扰的影响。实验结果表明，长喙毛茛泽泻种群能成功地实施迁地保护。     

长喙毛茛泽泻的花器官发生

用扫描电镜对长喙毛茛泽泻的花器官发生进行了观察。该种的花器官发生在泽泻科中既典型又比较特殊。其特殊之处在于从花原基的发生直至最外轮６枚雄蕊原基的发生过程存在单向发育：３个萼片和原基和３个花瓣原基的发生存在次序性,萼片原基和花瓣原基均为顺时针发生,邻近花序侧生分支复合芽的萼片原基和花瓣原基倾向于优先发生;     

濒危植物——长喙毛茛泽泻的受精作用及胚和胚乳的发育

长喙毛茛泽泻Ranalisma rostratum Stapf的配子融合开始较早,但精核与极核融合速度较快。精核与珠孔极核融合后即移向胚囊合点端与另一极核再融合形成初生胚乳核。初生胚乳核第一次分裂后形成两个细胞,以后珠孔端胚乳细胞再进行游离核分裂,胚乳发育属于沼生目型。开花后两天,合子分裂,八分体呈4层,每层呈两个细胞方式排列胚胎发生属于石竹型。     

长喙毛茛泽泻（泽泻科）的交配系统研究

对濒凶植物长喙毛茛泽泻的交配系统作了综合研究。结果理：该种的花粉粒和柱头较平滑,花内分泌细胞存在但欠发达,开花前花粉萌发率较高而开花１ｈ后花粉萌发能力急剧衰退,花粉／胚珠比较低,花部综合特征与其花前期闭花授粉的交配习性相适应。该种的自然居群及实验居群中均未观察到花间的虫媒传粉,仅有极小型昆虫起花内传粉作用,亦未检出风媒花粉流。     

长喙毛茛泽泻胚中营养物质的积累与消耗

长喙毛茛泽泻是一种水生濒危植物。它的种子中没有胚乳,营养物质以淀粉和帽白体的形式贮藏在胚中。胚不同部位物质积累情况差异较大,下胚轴和子地细胞中的淀粉,蛋白体数目多,体积大,胚芽和胚根分生细胞中只贮藏有少量的淀粉粒和蛋白体。     

迁地保护中普通野生稻和长喙毛茛泽泻种群动态及评价

通过对江西东乡含濒危植物普通野生稻（Ｏｒｙｚａｒｕｆｉｐｏｇｏｎ）和长喙毛茛泽泻（Ｒａｎａｌｉｓｍａｒｏｓｔｒａ－ｔｕｍ）的群落在余江县实施重建,研究并评价了迁地保护后的濒危植物种群动态。结果表明,普通野生稻种群呈迅速增长的趋势,分布面积迅速扩大,有性繁殖正常,实生苗补充在种群增长中起重要作用;无性繁殖旺盛,对新生境表现出良好的适应性。在两年实验研究期间,长喙毛茛泽泻种群数量和分布面积迅速扩大,在良好生境中通过有效扩散使种群占据塘底有利生境,并通过无性繁殖及短暂有性繁殖实现种群更新。两个濒危种迁地保护是成功的,杂草是阻碍两个濒危植物种群增长的主要原因,水位控制是实验塘生境管理的重要手段。     

长喙毛茛泽泻和冠果草种子贮藏及萌发特性（简报）

开花后30d的长喙毛茛泽泻种子生活力较高,60d起急剧下降;冠果草种子生活力明显高于长喙毛茛泽泻。两类种子均宜水浸贮藏。于贮后的长喙毛茛泽泻种子不能萌发,而冠果草种子仍有较高的萌发率。     

长喙毛茛泽泻的种群分布格局和群落内种间关联

长喙毛茛泽泻茶陵种群呈斑块分布,格局类型为聚集分布型,每个亚种群也呈聚集分布,但聚集强度不同。长喙毛茛泽泻与其几个主要伴生种的相关性经测定结果是：与莼菜及黄花狸藻之间的相关性不显著;与柳叶箬、双穗雀稗及石龙尾之间正相关显著;与疏勿蓼之间负相关显著,长喙毛茛泽泻种子近距离传播以及无性繁殖特性是造成其聚集分布的主要原因。柳叶箬、双穗雀稗和石龙尾对长喙毛茛泽泻具有极强的竞争作用。     

The Development of Male and Female Gametophyte in an Endangered Plant—Ranalisma rostratum Stapf (Alismataceae)

Ranalisma rostratum Stapf is a rare and endangered species． This paper deals with the development of its male and female gametophytes and probes the relationship between the process of reproduction and the cause which made this species endangered． The meiosis of microspore mother cells is successive cytokinesis and the microspore tetrads are isobilateral． Pollen grains are 3-celled when shed． The ovule is anatropous,bitegmic and tenuinucellate． The micropylar dyad cell usually desenerates soon after its formation, and the chalazal dyad cell develops into a Allium type embryo sac． During the development of embryo sac both polar nuclei are respectively located at the two ends of central cell,and they maintain this situation until the micropylar polar nucleus takes part in fertilization． Features of the embryo sac of Ranalisma rostratum Stapf are discussed．     

The Fertilization and the Development of Embryo and Endosperm in an Endangered Plant—Ranalisma rostratum Stapf (Alismataceae)

Ranalisma rostratum Stapf is a rare and endangered species． This paper deals with the fertilization and the development of embryo and endosperm in this plant．The embryogenesis is of Caryophyllad type and the development of endosperm belongs to Heobial type．Before fertilization,the two polar nuclei are located respectively at both ends of embryo sac. In most angiosperms with two polar nuclei,the polar nuclei may fuse eiher before fertilization to form a secondary nucleus or during fertilization called triple fusion． In Ranalisma rostratum Stapf, however, it is found that only in case when the micropylar polar nucleus is fertilized,it can move to the chalazal end and fuse with the chalazal polar nucleus．This phenomenon is very rare and the process must take more time to fulfil fertilization both polar nuclei． This feature of fusion of polar nuclei is therefore thought as a primitive character from the view of phylogeny．